NGC2244CXO ivo://nasa.heasarc/ngc2244cxo NASA/GSFC HEASARC Wang et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source This table contains the point source catalog based on the first high spatial resolution X-ray study of NGC 2244, the 2 Myr old stellar cluster in the Rosette Nebula, using Chandra. Over 900 X-ray sources are detected within 20 arcminutes of the cluster central position (J2000.0 RA and Dec of 6 31 59.9, +4 55 36); 77% of these X-ray sources have optical or FLAMINGOS NIR stellar counterparts and are mostly previously uncataloged young cluster members. The X-ray-selected population is estimated to be nearly complete between 0.5 and 3 M<sub>solar</sub>. A number of further results emerge from the analysis: (1) The X-ray luminosity function (XLF) and the associated K-band LF indicate a normal Salpeter IMF for NGC 2244. This is inconsistent with the top-heavy IMF reported from earlier optical studies that lacked a good census of < 4 M<sub>solar</sub> stars. By comparing the NGC 2244 and Orion Nebula Cluster XLFs, the authors estimate a total population of ~2000 stars in NGC 2244. (2) The spatial distribution of X-ray stars is strongly concentrated around the central O5 star, HD 46150. The other early O star, HD 46223, has few companions. The cluster's stellar radial density profile shows two distinctive structures: a power-law cusp around HD 46150 that extends to ~0.7 pc, surrounded by an isothermal sphere extending out to 4 pc with core radius 1.2 pc. This double structure, combined with the absence of mass segregation, indicates that this 2 Myr old cluster is not in dynamical equilibrium. (3) The fraction of X-ray-selected cluster members with K-band excesses caused by inner protoplanetary disks is 6%, slightly lower than the 10% disk fraction estimated from the FLAMINGOS study based on the NIR-selected sample. (4) X-ray luminosities for 24 stars earlier than B4 confirm the long-standing log (L<sub>X</sub>/L<sub>bol</sub>) ~ -7 relation. The Rosette OB X-ray spectra are soft and consistent with the standard model of small-scale shocks in the inner wind of a single massive star. This table was created by the HEASARC in July 2008 based on electronic versions of Tables 2, 3, 4, 5 and 6 of the reference paper which were obtained from the electronic ApJ web site. This is a service provided by NASA HEASARC . 2008ApJ...675..464W https://heasarc.gsfc.nasa.gov/W3Browse/all/ngc2244cxo.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=ngc2244cxo& GET text/xml 180 99999 true 98.099331 4.630185 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=ngc2244cxo GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_ngc2244cxo&Action=More+Options&Action=Parameter+Search&ConeAdd=1 CHANDRA 0.0166666666666667 X-ray public ngc2244cxo NGC 2244/Rosette Nebula Chandra X-Ray Point Source Catalog name Source IAUC Designation meta.id;meta.main char nullable ra Right Ascension degree pos.eq.ra;meta.main double nullable dec Declination degree pos.eq.dec;meta.main double nullable counts Estimated Net 0.5-8 keV Band Extracted Counts ct phot;em.X-ray double nullable counts_error Average Upper and Lower 1-Sigma Errors in Next Extracted Counts ct stat.error;phot;em.X-ray double nullable log_lx Log of Absorption-Corrected 2-8 keV Band Luminosity log(erg/s) phys.luminosity;em.X-ray double nullable twomass_name 2MASS Source Designation meta.id.cross char nullable jmag 2MASS J Band Magnitude mag phot.mag;em.IR.J double nullable vmag The V Band Magnitude mag phot.mag;em.opt.V double nullable log_nh Log of Best Fit Column Density log(H-atoms/cm^2) phys.columnDensity double nullable log_bck_prob Log of Probability That All 0.5-8 keV Counts from Background stat.probability double nullable log_lx_obs Log of 0.5-8 keV Band Luminosity log(erg/s) phys.luminosity;em.X-ray double nullable lii Galactic Longitude degree pos.galactic.lon double nullable apec_kt Best Fit Plasma Temperature (keV) keV phys.temperature double nullable log_em Log of Emission Measure of Model Spectrum log(cm^-3) phys.emissMeasure double nullable log_bck_prob_limit Limit Flag for Log of Background Probability meta.code;stat.probability char nullable log_nh_flag Flag [i] Indicates Log NH Frozen in the Fits meta.code;phys.columnDensity char nullable mjd95_number Massey, Johnson, & Degioia-Eastwood (1995) Source ID meta.id.cross short nullable log_pl_norm_neg_err Lower 90% Confidence Interval in Log of Model Power Law Normalization log(cm^-3) stat.error;stat.fit.param double nullable significance Photometric Significance stat.likelihood double nullable source_flag Flag [M,S] Indicates Either Main or Secondary Source meta.code char nullable rmag The R Band Magnitude mag phot.mag;em.opt.R double nullable log_pl_norm_pos_err Upper 90% Confidence Interval in Log of Model Power Law Normalization log(cm^-3) stat.error;stat.fit.param double nullable apec_kt_pos_err Upper 90% Confidence Interval in kT keV stat.error;phys.temperature double nullable flamingos_id The FLAMINGOS (Section 3.1) ID meta.id.cross char nullable apec_kt_neg_err Lower 90% Confidence Interval in kT keV stat.error;phys.temperature double nullable log_em_neg_err Lower 90% Confidence Interval in Log EM log(cm^-3) stat.error;phys.emissMeasure double nullable hmag 2MASS H Band Magnitude mag phot.mag;em.IR.H double nullable log_sb_lx_obs Log of 0.5-2 keV Band Luminosity log(erg/s) phys.luminosity;em.X-ray.soft double nullable spectral_index_pos_err Upper 90% Confidence Interval in Gamma keV stat.error;spect.index;em.X-ray double nullable imag The I Band Magnitude mag phot.mag;em.opt.I double nullable bii Galactic Latitude degree pos.galactic.lat double nullable apec_kt_flag Flag [i] Indicates kT Frozen in the Fits meta.code;phys.temperature char nullable kmag 2MASS K_S Band Magnitude mag phot.mag;em.IR.K double nullable notes Additional Notes meta.note char nullable bck_counts Background 0.5-8 keV Band Extracted Counts ct phot;instr.background;em.X-ray double nullable source_anomaly_flag Flag Indicates Source Anomalies meta.code char nullable bc02_number Berghofer & Christian (2002) Source ID meta.id.cross short nullable log_hb_lx_obs Log of 2-8 keV Band Luminosity log(erg/s) phys.luminosity;em.X-ray.medium double nullable spectral_index Best Fit Power Law Photon Index keV spect.index;em.X-ray double nullable ps02_number Park & Sung (2002) Source ID meta.id.cross short nullable hb_counts Estimated Net 2-8 keV Band Extracted Counts ct phot;em.X-ray.medium double nullable opt_name Optical Designation meta.id.cross char nullable umag The U Band Magnitude mag phot.mag;em.opt.U double nullable twomass_flags The 2MASS Photometric Quality Flags meta.code.qual;phot char nullable spect_notes Flag [2T,H] Indicates Two-Temperature Model Used or Fit Performed by Hand meta.code char nullable log_hb_lx Log of Absorption-Corrected 2-8 keV Band Luminosity log(erg/s) phys.luminosity;em.X-ray.medium double nullable log_em_pos_err Upper 90% Confidence Interval in Log EM log(cm^-3) stat.error;phys.emissMeasure double nullable median_energy Background-Corrected Median 0.5-8 keV Photon Energy keV phys.energy double nullable error_radius Estimated Random Component of Position Error (arcsec) arcsec stat.error;pos double nullable psf_fraction Fraction of PSF (at 1.497 keV) within Extraction Region instr.det.psf double nullable halpha_mag The H-alpha Band Magnitude mag phot.mag;em.line.Halpha double nullable usno_name USNO B1.0 Source Designation meta.id.cross char nullable log_nh_pos_err Upper 90% Confidence Interval in Log NH log(H-atoms/cm^2) stat.error;phys.columnDensity double nullable log_pl_norm Log of Model Power Law Normalization log(cm^-3) stat.fit.param double nullable alt_name Alternative Source Designation meta.id char nullable exposure Effective Exposure Time (s) s time.duration;obs.exposure double nullable bmag The B Band Magnitude mag phot.mag;em.opt.B double nullable source_variable_flag Flag Indicates Variability Characterization meta.code char nullable off_axis Off-Axis Angle (arcmin) arcmin instr.offset double nullable log_nh_neg_err Lower 90% Confidence Interval in Log NH log(H-atoms/cm^2) stat.error;phys.columnDensity double nullable spectral_index_neg_err Lower 90% Confidence Interval in Gamma keV stat.error;spect.index;em.X-ray double nullable source_number Sequential Identification Number for Each Source in Catalog meta.id;src short nullable "__x_ra_dec" System unit vector column double nullable "__y_ra_dec" System unit vector column double nullable "__z_ra_dec" System unit vector column double nullable "__row" System index column char nullable